Systems and methods for primary-side regulation in off-line switching-mode flyback power conversion system

Abstract

Switching-mode power conversion system and method thereof. The system includes a primary winding configured to receive an input voltage, and a secondary winding coupled to the primary winding and configured to, with one or more first components, generate, at an output terminal, an output voltage and an output current. Additionally, the system includes an auxiliary winding coupled to the secondary winding and configured to, with one or more second components, generate, at a first terminal, a detected voltage. Moreover, the system includes an error amplifier configured to receive the detected voltage and a first reference voltage and generate an amplified voltage based on at least information associated with a difference between the detected voltage and the first reference voltage. Also, the system includes a compensation component configured to receive the amplified voltage and generate a second reference voltage based on at least information associated with the amplified voltage.

What is claimed is: 
     
       1. A system controller for regulating a power conversion system, the system controller comprising:
 an error amplifier configured to receive an input signal and a first reference signal and generate an amplified signal based on at least information associated with a difference between the input signal and the first reference signal; 
 a compensation component configured to receive the amplified signal and generate a second reference signal based on at least information associated with the amplified signal; 
 a summation component configured to receive the second reference signal and a predetermined reference signal and generate the first reference signal, the first reference signal being equal to a sum of the second reference signal and the predetermined reference signal, the first reference signal being different from the second reference signal; 
 a signal generator configured to receive at least the amplified signal and generate one or more control signals based on at least information associated with the amplified signal; and 
 a driving component configured to receive the one or more control signals, generate a drive signal based on at least information associated with the one or more control signals, and output the drive signal to a switch to affect a first current flowing through a primary winding of a power conversion system. 
 
     
     
       2. The system controller of  claim 1  wherein the compensation component includes a gain component associated with a predetermined gain and is further configured to generate the second reference signal equal to the amplified signal multiplied by the predetermined gain in magnitude. 
     
     
       3. The system controller of  claim 2  wherein the signal generator is configured for pulse-width modulation or pulse-frequency modulation. 
     
     
       4. The system controller of  claim 2  wherein the signal generator is configured for pulse-width modulation and pulse-frequency modulation. 
     
     
       5. The system controller of  claim 1  wherein the error amplifier is further configured to generate the amplified signal increasing with an output current in magnitude. 
     
     
       6. The system controller of  claim 1  wherein the error amplifier, the compensation component, the summation component, the signal generator, and the driving component are located on a chip. 
     
     
       7. The system controller of  claim 6  wherein the chip includes a terminal coupled to the error amplifier, the compensation component, and the signal generator. 
     
     
       8. The system controller of  claim 1  wherein:
 the power conversion system further includes a secondary winding associated with an output voltage and an output current; and 
 the compensation component is further configured to generate the second reference signal such that the output voltage is substantially independent of the output current. 
 
     
     
       9. The system controller of  claim 1  wherein the compensation component is further configured to increase the second reference signal with an output current. 
     
     
       10. A system controller for regulating a power conversion system, the system controller comprising:
 an error amplifier configured to receive an input signal and a predetermined reference signal and generate an amplified signal based on at least information associated with a difference between the input signal and the predetermined reference signal; 
 a compensation component configured to receive the amplified signal and generate a compensation current based on at least information associated with the amplified signal; 
 a signal generator configured to receive at least the amplified signal and generate one or more control signals based on at least information associated with the amplified signal; and 
 a driving component configured to receive the one or more control signals, generate a drive signal based on at least information associated with the one or more control signals, and output the drive signal to a switch to affect a first current flowing through a primary winding of a power conversion system; 
 wherein the compensation component is further configured to generate, with one or more resistors, an offset voltage based on at least information associated with the compensation current to change the input signal by the offset voltage; 
 wherein the compensation component includes a compensation transistor configured to generate the compensation current based on at least information associated with the amplified signal. 
 
     
     
       11. The system controller of  claim 10  wherein the error amplifier, the compensation component, the signal generator, and the driving component are located on a chip. 
     
     
       12. The system controller of  claim 11  wherein the chip includes a terminal coupled to the error amplifier, the compensation component, and the signal generator. 
     
     
       13. The system controller of  claim 10  wherein:
 the compensation component includes a compensation resistor associated with a compensation resistance; and 
 the compensation component is further configured to generate the compensation current equal to the amplified signal divided by the compensation resistance in magnitude. 
 
     
     
       14. The system controller of  claim 10  wherein the compensation component is further configured to increase the compensation current with an output current. 
     
     
       15. The system controller of  claim 10  wherein:
 the power conversion system further includes a secondary winding associated with an output voltage and an output current; and 
 the compensation component is further configured to generate the compensation current such that the output voltage is substantially independent of the output current. 
 
     
     
       16. A system controller for regulating a power conversion system, the system controller comprising:
 an error amplifier configured to receive an input signal and a predetermined reference signal and generate an amplified signal based on at least information associated with a difference between the input signal and the predetermined reference signal; 
 a compensation component configured to receive the amplified signal and generate a compensation current based on at least information associated with the amplified signal; 
 a signal generator configured to receive at least the amplified signal and generate one or more control signals based on at least information associated with the amplified signal; and 
 a driving component configured to receive the one or more control signals, generate a drive signal based on at least information associated with the one or more control signals, and output the drive signal to a switch to affect a first current flowing through a primary winding of a power conversion system; 
 wherein the compensation component is further configured to generate, with one or more resistors, an offset voltage based on at least information associated with the compensation current to change the input signal by the offset voltage; 
 wherein the compensation component includes a compensation amplifier configured to receive the amplified signal and output a first voltage based on at least information associated with the amplified signal for generating the compensation current. 
 
     
     
       17. The system controller of  claim 16  wherein the error amplifier, the compensation component, the signal generator, and the driving component are located on a chip. 
     
     
       18. The system controller of  claim 17  wherein the chip includes a terminal coupled to the error amplifier, the compensation component, and the signal generator. 
     
     
       19. The system controller of  claim 16  wherein:
 the compensation component includes a compensation resistor associated with a compensation resistance; and 
 the compensation component is further configured to generate the compensation current equal to the amplified signal divided by the compensation resistance in magnitude. 
 
     
     
       20. The system controller of  claim 16  wherein the compensation component is further configured to increase the compensation current with an output current. 
     
     
       21. The system controller of  claim 16  wherein:
 the power conversion system further includes a secondary winding associated with an output voltage and an output current; and 
 the compensation component is further configured to generate the compensation current such that the output voltage is substantially independent of the output current. 
 
     
     
       22. A method for regulating a power conversion system, the method comprising:
 receiving an input signal and a first reference signal; 
 processing information associated with the input signal and the first reference signal; 
 generating an amplified signal based on at least information associated with a difference between the input signal and the first reference signal; 
 receiving the amplified signal; 
 processing information associated with the amplified signal; 
 generating a second reference signal based on at least information associated with the amplified signal; 
 receiving the second reference signal and a predetermined reference signal; 
 processing information associated with the second reference signal and the predetermined reference signal; 
 generating the first reference signal equal to a sum of the second reference signal and the predetermined reference signal, the first reference signal being different from the second reference signal; 
 receiving at least the amplified signal; 
 processing information associated with the amplified signal; 
 generating one or more control signals based on at least information associated with the amplified signal; 
 receiving the one or more control signals; 
 processing information associated with the one or more control signals; 
 generating a drive signal based on at least information associated with the one or more control signals; and 
 outputting the drive signal to a switch to affect a first current flowing through a primary winding of a power conversion system, the power conversion system further including a secondary winding associated with an output voltage and an output current. 
 
     
     
       23. The method of  claim 22  wherein the second reference signal is equal to the amplified signal multiplied by a predetermined gain in magnitude.